Some things I wish they would do eventually in iOS
BiteSMS like texting, it is so much easier that it is the thing that most people missed most from JB. I can text while my phone syncs and it will do both things enabling you to do more.
Sounds - iOS 5 goes farther with sounds than before but I would like them to let you totally control system sounds and remove the stupid ones.
Stock icons - Finally allow the stock icons to be deleted. In every version of the firmware so many people have the same set of stock apps in some unused or misc folder.
Theming - this will NEVER happen from Apple but I would love a firmware that allows theming even if it's Apple regulated and also cost 99 cents.